Conventional pool pumps are operable at a finite number of predetermined speed settings. These speed settings correspond to the range of pumping demands of the pool at the time of installation. Factors such as the volumetric flow rate of water to be pumped, the total head pressure required to adequately pump the volume of water, and other operational parameters determine the size of the pump and the proper speed settings for pump operation. Once the pump is installed, the speed settings may not be readily changed to accommodate changes in the pool conditions and/or pumping demands. For example, flow rates through these pumps change over time because the system's total dynamic head changes as dirt and debris accumulate in the pool filter and strainers. This increase in flow resistance causes the conventional pumps to lose flow as the system gets dirty. Due to this loss of flow and the inability to adjust settings, such systems may not maintain desired turnover rates in the pool. As a result, such systems fail to meet health department requirements for commercial swimming pool applications, which require a minimum number of turnovers per day.
Newer pool pump systems include variable speed drives, allowing them to operate at any number of speeds to maintain the above-described factors independent of changes in the pool conditions and/or pumping demands. These pumps are controlled to run at different speeds and flows to maintain one or more control factors and to accommodate changing water supply needs of a pool, such as periodic operation of a water feature. Current control of such systems only focuses on a number of manual and/or scheduled operations, programmable by a pool user, and generally may not consider overall flow or turnover parameters.